A number of different types of telecommunication networks and telecommunication protocols currently exist. For example, mobile networks use protocols that allow mobile device users to move from one location to another. Examples of mobile devices include, without limitation, mobile phones, personal digital assistants (PDAs), and laptops, etc.
Fixed networks provide data services in a fixed environment. An example of a fixed network is a DSL (digital subscriber line) network. A fixed network may be fixed wireless or fixed wireline. Fixed wireless is an alternative to fixed wireline, e.g., landline, coaxial cable, and copper connections. Fixed wireless refers to the operation of wireless devices or systems in fixed locations such as homes and offices. An example of fixed wireless is broadband wireless access in a home.
In addition, a number of different types of data services and different methods of communicating between or among devices currently exist. For example, Short Message Service (SMS) is a service for sending text messages to mobile phones and other devices.
As another example, Multimedia Messaging Service (MMS) is a communications technology that allows users to exchange multimedia messages and content between MMS-capable mobile phones and other MMS-capable devices. MMS requires users to have the same or compatible clients on both ends (or complex translation infrastructure).
Wireless Application Protocol (WAP) is a specification for a set of communication protocols to standardize the way that wireless devices, such as cellular telephones and radio transceivers, can be used for Internet access, including e-mail, the World Wide Web, newsgroups, and instant messaging, etc. WAP-based services require special browsers or infrastructure to access services. While Internet access has been possible in the past, different manufacturers have used different technologies.
IP Multimedia Subsystem (IMS) is defined by Third Generation Partnership Project (3GPP) as an architecture for multimedia sessions over IP. IMS and other advanced IP-based services such as Voice over IP (VoIP), which rely on new network topologies and new clients for access, may be considered separate networks as their architecture may fail to consider interoperability, a subscriber's identity, target client, or services beyond basic voice services.
Many other types of data services and methods of communicating exist, such as creating separate networks for IMS or other advanced services which also result in creating isolated services and islands of communities. This situation poses a barrier to interoperability.
Additionally, within these various mobile and fixed networks, there are multiple channels via which users can originate and/or receive messages or other forms of communication. In many cases, a single subscriber may have multiple identities, including different identities for phone-based services, such as voice and SMS or MMS, as well as identities for other communication channels such as instant messaging and e-mail.